Range-finder.



G, FECKY RANU HNULR.

APPLICATION HULP hULY I3. 1914.

1,269,171 laltvnwl 5min H, 1918 ZENtEISfSHEEI G. FECKER.

RANGE FINDER.

APPucATmn msn 1uLY1a.s914.

1,969, 1 7 l Patented June 11, 1918.

3 SHEETS-SHEET 2.

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2K9. Wm@ my@ G. FECKER.

RANGE FINDER.

APPLICATION FILED 1uLv:3.ws4.

1 ,259, 1 '7 l Patented Junell. 1918.

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@(35% I A 17% @MWA /fm @L UNITEDv STATES PATENT OFFICE.

, i GQTTLIEB ECXER, CLEVELAND, HIQ,` ASSIGNOR TO THE WARNER AND SWASEY COMPANY, QF CLEVELAND, OHIO, COBPQBTION .0F OHIO.

RANGE-rimane.

Specinoatlon of Letters lfatent.

Patented June 11, 1918.

Application yled July 13, 1914. Burial No. 850,643.

To all fwtmlt it may concern.'

Be it known that I, Gorrmn FQKER, a citizen of the United States, 'residing at Cleveland,- in theNcounty of Cuyahoga and curacy required State of Ohio, have invented a certain new and usefulIrn. rovement in Range-Finders, of which, theA ollowing is a full, clear, and

exact description.

. This invention relates to improvements in coincidence telemeters,-that is to say, to the sort of range finders which include two tele scopeslhavmg normally parallel axes and a common eye ieee in which appear the two images -from t e respective telescopes located on opposite sides of a line which divides the field into two image fields, together with means for causing such angular deflection of one of the telescopes as. will causerthe alinement or coincidence of the two images, and means for indicating the ,extent of such deflection insuitable terminology.

Generally speaking, the object of the invention is to roduce a self contained and easily portab e instrument which is not likely 'to get out of order, and which will give quickly, and with the degree of acinformation as to the distance of any object from the instrument, 4within the limits 'of its'capacity.

The instrument in which the invention is embodied is believed to be unique in that it is the rst self contained range finder which is self collmating,that is to say, it con tains wholly within itself means for determining' whether the two telescopes are ex actly collimated, as well as the means by which this condition may be brought about when the indicatorfis at zero.

` The invention consists in the construction and combination of parts shown in the drawing and hereinafter described and definitely pointed out in the appended claims.

In the drawing,`Figure 1 is a plan view of the instrument when the casing4 which covers the telescopes is removed, and when the base line tube has its middle broken away,'and=its right `end `and the contents thereof sectioned and a portion of the left end also broken away and sectioned. Fig. 2 is a front elevation of the left end of the instrument, the 'base line tube being shown in verticalsection. Fig. 3 is a sectional yiew in the plane of line 33 on F194. Fig. 4

B. Each of these is composed of several rigidly connected parts. The base member A is a tube which when the instrument is in use occupies a substantiallyhorizontal position with its axis at right angles to a hne passing therefrom to the object under observatlon. A bracket plate C is fixed to this tube and thereby becomes in effect a part of the base member.

The head B is built up of Yseveral parts, viz., the body b, and two casing members b1, bffall of which are rigidl connected together. The bracket plate carries a horizontal stud c, on which the body b of the head is pivoted, said body being held on said stud by a screw c1.

In this head and protected by the outer casing members thereof are two telescopes, which are so mounted that their optical axes may be parallel with one another, and with the mechanical axis of the head, and lie on opposite sides of said mechanical axis, and in the same vertical plane therewith.

These two telescopes have a common eye piece D which is fixed to the body b, and includes a right angle reflecting prism d, which is so set that the line in which the two reflecting planes intersect is horizontal and at right angles to the vertical lane in which the optical axis of the two te escopes lie. This line therefore divides the field into two image fields, viz., lone above the line The upper telescope includes the objective lens G and its cell g and the half inverting reflecting prism F arranged in proper relation to said objective and the eye piece D, wherefore the image from this telescope appears inverted in` the upper image field of the eye piece.

The lower telescope is fixed to the body b, so that its optical axis is preferably at rlght angles to the base line (to be presently explained) of the instrument. The normal position of the upper telescope (when the indicator to be hereinafter described shows zero) is such that its optical axis is parallel with the optical axis of the lower telescope. The upper telescope, however, is capable of angular displacement, and this is because both the objective G and the prism F of this telescope are carried on an arm K which is pivoted to the body b by the screw c, whose axis is at right angles to but in the saine Vertical plane which includes the optical axes of the two telescopes und the mechanicalV axis about which the head B turns.

In the base tube A adjacent to the lower telescope is a reflecting pentaprism N, which, when the instrument is being used to measure distances, cooperates with another refiecting pentaprism M in the opposite end of the base tube, so as to refiect the light rays which enter said tube through hole a* directly in front of the latter prism, so that they are directed into the lower telescope. The base line of the instrument (which is the base line of the triangle whose perpendicular is to be ascertained by the instrument) is an imaginary line drawn from and at right angles to the central light ray which enters tube A through the opening a4 and the central light ray which enters the lower telescope, the length of said line being equal to the length of any light ray which passes from prism to prism. In the instrument this base line is 31% inches long.

The prism N is mounted in the holder 'n which is pivoted within the tube A on a spindle n1 having a vertical axis, said spindle projecting upward out through the tube, and there being connected 'with it outu side of the tube an arm n2, by means of which the prism may be swung into the operative position, such that it reflects the light rays `from prism M into the lower telescope.

Now, vto' use this instrument to measure distances, it is fixed in such position that the axis of the tube A is substantially horizontal and at right angles to a line passing to the objectunder observation. The prism N is now in the operative position described.

iNow the light rays from the object whose distance is to be measured, as, for example, the flag pole-or the vertical. corner of a building, will enter the hole a4 at right angles to the base line aforesaid, and will be reflected from prism M to prism N, and thence into the lower telescope. The image the object will appeal' in the eye piece right side up in the lower image field. At the same time the light rays from the same object will pass directly into the upper telescope and the image of the same object will appear half inverted in the upper field of the eye piece, but at a greater or, less distance to the left of the lower image.

By swinging the arm K upon its pivot the optical axis of the upper telescope may be made to proceed directly to the distant object. When this has been brought about, the two images in the two image fields will then appear with their corresponding upright lines in alinernent, and on opposite sides of the line which divides the image field. lVhen the instrument is in this condition, a right angle triangle has been formed, of which the base corresponds to the base line of the instrument before explained, which, in the instrument shown, is 31% inches long, and whose perpendicular is the distance ofthe object from the instrument. If one knows the angular deflection of the 'upper telescope required to bring about the stated coincidence of corresponding parts of the two images, he has the data for calculating the value of the perpendicular of said triangle, or, in other words, t e distance of the object from the instrumejt.

The deiection of the upper telescope `is due, as stated, to the swinging of the arm K upon which the objective and the prism are mounted. A screw P having a hard conical point is screwed through a boss b5 which is a part of the body Z, and the Ipoint bears against the wearing plate p carried by said swinging arm. A spring p1 acts -to swing the arm against the screw and resists the opposite movement which is produced by screwing in the screw. This screw carries the indicator dial R which is provided with a circumferential fiange fr which is graduated for cooperation with the pointer r1.'

This indicator is adjustablyconnected with saiV screw, by means to be explained later.

his dial might be graduated to show in minutes and seconds the angular deflection of the upper telescope. If it were, then the operator could, because he knows th'e length, 31% inches, of the base line of the triangle which has been erected, calculate the length of the perpendicular of said triangle, which is the distance of the object from the instrument. B ut preferably the graduations iof the dial are'in terms of translated equivalents-in this articular instrument of the angular deliection of the upper telescope, viz., in figures representing in feet the length of the perpendiculars of the triangles having always the same base line,- and a suitable number of the various opposite angles produced by the defiection-of said telescope. The described instrument is practically eiicient,for,al1 `distances from 400 to 18000 fecit cdthegraduations shovs7 a suicient numbenofthese distances for practical purposes. t

From` the foregoing it will be clear that in the instrument there yare two optical trains' terminating in a common eye piece. The objective opening of these two optical trains are at opposite ends of a base line of known length within the tubular base member. One of these trains includesthe lower telescope whose optical aXis is at right angles to said base line; the other train includes the upper telescope whose optical axisI is normally parallel with the axis of the lower telescope.

The prism F which is carried by the swinging arm is itself secured in a holder f1 which is part of a lever f which is pivoted to said Swingin arm K on an axis at right angles to the pivot of said arm. A spring f2 engages this lever and holds it against the end of a screw T, which screw is mounted in the swinging arm, and has a little pinion t fixed to it. This pinion is engaged by a long pinion t1 fast to a rotating shaft t2 which is mounted in the body b. An operating shaft ts, which projects out through the casing so that the operator may turn it.,

- is connected with shaft t byl an intermediate` member t* having a universal joint connection with both shafts. This mechanism will remain operative, irrespective of the position of the swinging arm and furnishes a means by which the position of the refleeting surface of the prism F relative to the optical axis of the telescope and the eye piece prism d may be varied. This enables the operator, by swinging this prism supporting lever, to cause the image in the upper field to move up or down, as required, to bring the lower part of said image into the desired relation to the horizontal line which divides the image, field. This is frequently desirable because one may, by properly positioning the entire instrument, bring the lower image into proper relation to the` di' vidingline. zThe adjustment of this lever, as before stated, is the means by which the upperl image may be brought into a corresponding relation to said dividing line.

Mention has been made of the fact that this instrument is self collimating. If one desired to determine whether or not the two telescopes are collimated,-that is to say, to determine whether the optical axes thereof are parallel, he will swing the prism N back out of operative position, and will then sight some distant object, and to whatever extent is necessarywill cause the swinging of the arm K until the two images are alined. He will then turn the entire head on the supporting stud "n distance of 180 degrees, and will then l .a ne object. l"I'the two images are not then in alinement, he knows that the instrument is not accurately colli- Vmated and proceeds to make the necessary indicator'needs adjustment with respect to the screw. He then turns Said screw and thereby Vdefiects the upper telescope until the two images do coincide. Then he swings the entire headf180 degrees upon the supporting mechanical axis; and if the images now coincide he knows that the two telescopes are collimated. In that event he readjusts the indicator to the Vzero position if necessary. The indicator disk is mounted on 4the screw adjacent to a iiange p3, against which said disk is forced by a spring p, which causes sufficient friction to cause the dial to turn with theserew but not enough to prevent the dial from being turned on the screw for adjustment purposes.

If, when the instrument 1s so tested, it appears that the two telescopes are not collimated, the position of the optical axis of the lower telescope may be changed by a move ment of the objective cell e horizontally as much as may be necessary. This is easily accomplished because the objective cell is secured in a clamp U which isl slidably supported on the body member b and is movable for adjustment purposes by the screw U1.

There are holes b", c in the casing mem-- ber Bx and the bracket C for the direct passage of light rays to the upper telescope. There are other holes b, c7 for the passage of light rays from tube A to the lower telescope; and there is alsoa hole al in tube A in alinement with the holes bi, c7 for the passage of direc-t light rays to the lower telescope when the prism N is moved out of operative position. t

The head may be stopped and held in either of the two positions thereof referred to by lugs Zr secured to said head,and the spring plungers W, W1, of which the first may be engaged by either lug, and both may enter either of two notches b in a liange on said head.

It is to be understood that the terms horib zontal and vertical, as herein used, are relatlve, and not absolute terms, becauseithe instrument will operate equally, well in whatever position in which it may be placed, rovided it is directed at a suitable object. hatl is to say, anobject havin outlines which are at right an les to the ine dividing the image field in t e eye piece.

Several so-called reflecting prisms are shown andjreferred to herein. But those skilled in this art will understand that it is only the reflecting qualities of these prisms that are made` use ofin the normal operafixed to said tion of the instrument,` and that therefore any suitable and properly arranged reflecting surfaces may be employed instead of the prisms.

Having described my invention, I claim:

1. A. range finder, which includes a tubular base member having an objective opening adjacent one end, and' two separated reflectors in said tubular member bounding the base line of the instrument, and a head which is rotatably supported on said base member, two telescopes supported by said. headI one fixed thereto with its optical axis parallel with and above the mechanical axis of the head, and the other telescope being located below the mechanical axis of the head and in such position, that its own axis will nor-- mally lie in the same vertical plane as the axis of the upper telescope and the mechanical axis of the'head,--said lower telescope being capable of angular deflection about an axis which lies in the same vertical lplane above mentioned, means for angularly dcflecting the second telescope, and means indicating in desired terminology the extent of such deflection.

2.v A range finder which includes a tubular base member having an objective opening adjacent one end, and two separated reflectors in said tubular member bounding the base line of the instrument, and a head which is rotatably supported on said base member, two telescopes supported by said head, one -liXed thereto with its optical axis parallel with and above the mechanical axis of the head, and the other telescope being located below the mechanical axis of the head and in Such position that its own axis will normally lie in the same vertical plane as the axis of the upper telescope and the mechanical axis of the heath-said lower telescope being capable of angular deflection about an axis which lies in the same vertical plane above mentioned, means for angularly deflecting the second telescope, and means indicating in desired terminology the extent of such deflection, means for fixing the head in either of two positions 180 apart, and means for displacing that reflector in the base line tube which is adjacent to said head.

3. A'range finder comprising a tubular base member having an objective opening adjacent one-end and containing, two reflectors which define the baseline of the instrument, a headlixed to said base member adjacent the end opposite to that at which the objective opening is formed, a telescope head in coperative relation withl the adjacentreflector in the base member, an arm which ispivoted to saidhea'd, a second telescope carried by said arm, means for turning said arm in its supporting axis, means for determining when the axes of the two telescopes* are parallel, and indicating means which move proportionately to Said angular deflection of said arm, said indicating means being adjustably connected with said means for turning said arm.

4. In a range finder, the combination of a horizontal frame member, two reflectors secured thereto at a known distance apart, and two normally collimated telescopes supported by said frame member with their optical axes normally parallel in the same vertical plane, one of said telescopes being fixed directly behind one reflector and the other telescope being mounted to swing out of the plane in which said optical axes lie but in a plane at right angles thereto, an eye piece common to both telescopes and having a right angle reflecting prism which is so set that the line in which its two .reflecting planes4 intersect is at right angles to the plane in which the optical axes of the two telescopes lie when they are parallel, and an indicator which moves in proportion to the said swinging movement of said movable telescope.

5.- In a range finder, the combination of a horizontal frame member, two reflectors secured thereto at a known distance apart, two normally collimated telescopes which are supported by said frame member with their optical axes normally parallel and in the sameA vertical plane, one of said telescopes being fixed directly behind one prism for coperati on therewith and the other telescope being mounted for angular deflection out of the plane in which said optical axes lie, but in a plane at right angles thereto,- the reflector which coperates with the first named telescope being movable into and out of operative position, means for causing the angular deflection of the other telescope, and an indicator which moves proportionately to the deflection of said telescope.

6. In a range finder, the combination of a horizontal frame member, two reflectors secured thereto at a known distance apart and two normally col-limated telescopes supported by said frame member with their optical axes normally parallel and in the same vertical plane, an eye piece common to both telescopes, which eye piece includes a reflecting prism whose rellecting planes intersect in a line which is at right anglesto the vertical plane in which the optical axes of said telesco es normally lie, the lower telescope being xed in operative relation to said eye piece and to the adjacent reflector-carried y the horizontal frame member, the upper telescope comprising an objective and a reflecting prism, an, arm which is pivoted to swing in a horizontal plane to which said objective is secured, a lever pivoted to said arm to which the prism of said telescope is secured, means for swinging said lever into any desired position, means for swinging said arm, and an indicator which moves proportionately to said arm.

which one of bnc above the other Lacan/1 7. A range linder which includes two optical trains that begin at opposite ends of a own base line, each train including a teleseope,-whch telescopes are arranged with their axes normally parallel and ina vertical plane which is at right angles to said base line, an arm to said telescopes is xed, which arm is pivoted on a vertical axis which is in the same vertical plane above mentioned, means for swinging said arm, and an indicator which moves proportionately to the angular movement of said arm, an eye piece which is common to both telescopes, said. eye piecehaving a right angle reflecting prism which is set so that the two reflecting surfaces meet in a plane at right angles to the plane which passes through the optical axes of both telescopes when. said axes are parallel, and reflectors respectively intermediat;x of said right ang e prism and the two telescopes. y

'8. In a range finder, the combination of a tubular `base member having an objective opening, a' telescope fixed with respect to said base member with its axis at right, angles to the optical axis of said base member, two reilectors' 'in said base member one directly behind said objective opening and one located adjacent said teiescope to refiect thereto the light' 'rays which enters said penng, 'a second telescope pivo'tally connected 4With Said base member on an axis 4whiclfis 85T at right angles to the f ptieal axis of said base member and which is capable of occupying a position such that its optical axis is parallel with the optical axis of the first mentioned telescope, means for deflectlng and for measuring the deflection of said lpivoted telescope,

an eye piece commo to oth telescopes, two reiectors located respectively between said two telescopes andsaid common eye piece, and a right angle reiiecting prism adjacent said eye piece which is set with its two reflecting surfaces respectively in the path of the light rays from the two i Lst named refiectors and with the line in which said surfaces meet at right angles to a plane Which passes through the optical axes of both telescopes, which said axes are parallel.

In a range finder, thef combination with a tubular base member having an objective opening, a telescope fixed with respect to said base member with its axis atright anglee to the optical axis of said base member, two refiectors in said base member one directly behind said objective opening and one adjacent said telescope whereby light rays entering said objective opening are reected into said telescope, an arm pivotally supported upon said base member upon an axis and which is at right angles to a plane which passes through the optical axis of the base member and the Optical axis of the fixed telescope, a telescope fixed to said pivoted arm, means for delecting and measuring the deflection of said arm, an eye piece common to both telescopes and having a right angle reflecting prism whose reecting surfaces meet in a line that is at right angles to a plane which passes through the optical axes of said two telescopes when said axes are parallel, a fixed refiector intermediate of the first named telescope and said right angle reiiecting prism, a lever pivoted to the pivcted arm referred to, a reiector carried by said iever for transmitting light rays .from the last named telescope to said right angle prism, and means to rock said lever upon its pivot. In testimony signature in the whereof, I hereunto aix my presence of two witnesses.

GOTTLIEB FECKER. Witnesses EDWARD P. BURBELL, EUGENE C. BROWN. 

